Photochemical activity of TiO₂nanotubes

Abstract

TiO 2 is well known as a low-cost, highly active photocatalyst of good environmental compatibility. Recently it was found that TiO 2 nanotubes promise to enable for high photocatalytic activity (PCA). In our experiments, we studied the photocatalytic activity and spectroscopic properties of TiO 2 nanotube arrays formed by the anodization of Ti. The PCA efficiency related to the decomposition of methylene-blue was measured. To obtain reliable data, the results were calibrated by comparing with standard materials like Pilkington Activ™ which is a commercially available self cleaning glass. The studies included a search strategy for finding optimum conditions for the nanotube formation and the investigation of the relationship between PCA and annealing temperature. TiO 2 nanotubes of different shapes and sizes were prepared by an anodization of Ti foil in different electrolytes, at variable applied voltages and concentrations. The photo-dissociation of methylene-blue was detected by UV-VIS spectroscopy. For the optimized material, an enhancement factor of 2 in comparison to the standard reference material was found. Furthermore, femtosecond-laser induced photoluminescence and nonlinear absorption of the material were investigated. Possibilities for a further enhancement of the PCA are discussed.

Interaction of Ultrafast Laser Pulses With Nanostructure Surfaces

“…Nanostructured porous thin films for catalysis applications can be prepared by glancing angle deposition (GLAD) [18]. Metal oxicde nanotubes and nanorods (nanowires) can be fabricated by Enhanced photochemical activity was demonstrated with TiO 2 nanotubes [51]. Moreover, TiO 2 nanostructures are interesting for water cleaning and disinfection [52].…”

“…Nanostructured surfaces enable local reshaping and guiding of light as well as modified optical, mechanical and chemical properties. Therefore, there is an ever increasing spectrum of applications reaching from optoelectronic components with enhanced emission rate or detection sensitivity [1], tailored or broadband absorption [2], highefficiency solar cells [3] and photocatalysis [4,5] to surface-enhanced spectroscopy techniques, friction control [6], bio-compatibility [7][8][9][10][11] and superhydrophobicity (including anti-corrosion, antiicing, anti-biofouling, and self-cleaning) [12,13,14]. High-spatial-frequency nanostructures can be tools for quantum experiments [15].…”